1. Field of the Invention
The invention relates to an active clamp circuit for flyback power converter operated in a DCM (discontinuous current mode) and a CCM (continuous current mode).
2. Description of the Related Art
A power converter can be operated in higher switching frequency for reducing the size of its transformer. The related prior arts can be found in U.S. Pat. No. 5,570,278 titled “Clamped Continuous Flyback Power Converter”, U.S. Pat. No. 6,069,803 titled “Offset Resonance Zero Voltage Switching Flyback Converter”, and U.S. patent application No. 20110305048 titled “Active-clamp circuit for quasi-resonant flyback power converter”.